基于LTE信号外辐射源雷达的同频干扰抑制算法

传统基于LTE信号外辐射源雷达的同频干扰抑制算法往往采用对同频干扰进行对消或抑制的策略，其优点是适用范围广，能应用在多种机会外辐射源雷达中，但是鲜有结合LTE信号本身特征进行同频干扰抑制的研究。针对于上述情况，提出一种基于信源分离和LTE信号特征相结合的同频干扰抑制方法。采用m-Capon算法对未知信源数量的入射信号进行波达角估计，获得接收信号的混合矩阵，通过最小二乘法分离信号。将分离的源信号进行并行互模糊处理，利用LTE主基站信号、同频信号以及目标信号在距离-多普勒域上的特征差异进行判决，识别目标信号。仿真结果表明：所提算法相对于传统基于LTE信号外辐射源雷达的同频干扰抑制算法具有更优的抑制效果，并且避免了传统的杂波对消过程；同时因采用并行处理，减少了多次计算互模糊相关导致的额外时间开销。

A Co-channel Interference Suppression Algorithm for LTE-based Passive Radar

The traditional co-channel interference suppression algorithms of LTE （long-term evolution）-based passive radar adopt the strategy of cancelling or suppressing the co-channel interference. They are widely used and can be applied to various illuminators of opportunity external radiation source radar. However, there are few studies on co-channel interference suppression by utilizing the characteristics of LTE signal. A co-channel interference suppression algorithm, which combines the sources separation technique and characteristics of LTE signal, is proposed. The proposed algorithm is used to estimate the direction of arrival of incident signals, obtain the mixing matrix, and separate the signals based on the least square method. Then the parallel cross-ambiguity correlation of the separated source signals is executed. The differences among the LTE main base station signal, the co-channel interference and the target echo in the distance-Doppler domain are used to identify the target. Simulated results show that the proposed algorithm has better suppression performance compared to the traditional co-channel interference suppression algorithms, and avoids the traditional clutter cancellation process. Meanwhile, the extra time assumption caused by multiple calculations of cross-ambiguity correlation can be reduced by means of parallel operation.